Reclaiming used lubricating oils



Jan. 22, 1935. Y F. G. BAENDER 11,988,773

RECLAIMING USED LUBRICATING OILS med 1pm 11, 1952 Patented Jan. 22, 1935 UNITED.

RECLAIMNG USED poeme/Armeens j ll'rederick JG. Boender,` lorvallisg-Qreg.

Application Aprilil, 19,32.; Sm-mno. .694x493 -2 claims. 01. 19e-145) My invention relates :to the :reclaiming of lubricating ,oils after 1 use ininternal combustion ,engines.

ft is wellfknown that lubricating oil used lin 'internal combustion vengines 'requires to ,be changedlat the end ofgdelmte periods, ,not `because of the destruction of its lubricating Aprop- ,erties,Y but because `it `has ,accumulated 'so much foreign matter andizbecome mixed With Waterand gasoline,l .or otherblightnpetroleum components to such f extent l:that tsifurtherguseais apt toabe injuriousritio the `moving :parts of the engine. e

Various attempts have been made-:to .devise a method suitable fior: reclaiming V,such .oil,. but .the oil nso reclaimed has `not as ,a Igeneral rule been favorably ,receivedfzby-fthe public, :largely due to thefact that its color is A,cleterring v,being .sodark as compared Withifresh, standardrlubricating .oil, as ztoimake ,an unfavorable impression ,and induce hesitancy onv the Jpart .of the upublic to .use the reclaimed foil; tract. such lreclaimed `oil has ;a:;greater ,lubricating value than lunused oil, for .thereason tbatithe.unsaturatedhydroearbons of :the unused` oilfarebroken. down and;drivenoff by :theeaction of 4:the engine .on the LoiLfand .the foreign particles .it vmay zoriginally .contain are senarated,. :so that. they @may be removed during the reclaiming-method. t Y. v Y

Difficulty has also been experiencedeiniremoving 4fthe gasoline and other light 'hydrocarbons and waterifromzthe rlubricating',oilfvvithout at :the same time ,crackingor Volatilizingfthelighter components. of the lubricating i oil andV fdestroy.- ing,V or f reducing iitskvalue as a lubricant.

The ,object :of my invention lis to provide a method i'forreclaiming Jand ypurifying Jused 'lubrieating oils without Wastage, and for restoringits original color..

Myiinventionialso provides a -method ley-Which, byproper controlof the `temperature-and pressure fa vlarger percentage f of #the higher for more volatile components Vof I-the r oil` may be separated from i the i oilibeing treatedyby which `to produce, if desired, a `heavier body-inthe lubricating'oil than .itbriginally'fhad ith imyinvention also :the vapors i and gases driven off" from vthe foil vmay be condensed `and saved for further treatment; preventing their escape Lto ythe atmosphere, which is=undesilrab1e becausesof:-their.disagreeable odor.

Myx inventionV provides a practical and economical apparatus )adapted fto carry out! my process. 'I attain :my aboveV obj ects l aiv Amethod which comprisesirst sludging fthe fused Alubricating l o'il to; induce :the `.precipitationofi its foreignmatter,

neutralizing @the body Jof "oil, then removingo "e .neutralizing Aagent land intermixing fullerrs earth or .other earthy substance with the 'body of-"oil, heating the resultant cornrnixture under constant stirring :in a closed llretortunderpressureto a temperatureof approximately 350 degrees iF'. to convertthe moisture inthe oil-into fstea'rn, then permitting .such steami to escape gradually-'sas to prevent carrying ioi of oil `particles vvif-ith' the steam, continuing the --heating but Araiisirgf-tle temperature to approximately- -450 `degrees Ff Lto distill 01T the `vola-tile components of `the oil-'not to `lbe retained, injecting small portions f V'Wa'-` terlintogthe heated oil nwhichiash into' steam-and carry off ithe suspended 'ne'vpartiolesvf` foreign matter from the loil, Vcooling l'thefoil-jfbefore eX- posing it kto l.the air, and Ailt'eririg-ithe* oil" to-'imovethe.fullersi-earth. 'i3 :My method and apparatus provided therefor arelhereinaffter-.described lindetail Withreference toithe accompanyingidrawing. @In the drawing: f 'Y j, f 1 Fig. 1 shows a preferred Aform of my apparatus I .inplo'y ifor carrying out rin-y -metlim'lofv reclaiming Ause'cl llubrieating--loik Vand `lig. V2 `shows lthe detailsofaconstruction of the collapsible mechanical vlstiriferfsprovide, removed frpmaehelretsrt.' Y I w r .Referrv' g-noW tothe-dravvingwLMy app comprises an open vesselor tank 1, provided?liv;V h a funnel-like bottom 2 =havi 'g'avalvecrtolled essere andgprovideawitha pipe 4 iediii a`sou-rce fofwornpressed air, not vvshovingy which discharges dntothe bottom-fofi\the :said k tankfiforI and meneurthrusthesoueeepipeeziiandlisltius 19, as a unit, and readily cleaned, since the filtered material will collect on the outside.

The retort 8 is provided with electrical heating elements 25 andwith a mechanical stirrer mounted on a horizontally arranged shaft 27 which ex-` tends thru one end wall of the retort and is pro-- vided with a driven pulley 28.

The stirrer 26 is connected by pivoted links .294i

to arms carried by the shaft 27, so that Vit. may be collapsed as illustrated in Fig.w 2`and insertedv thru a relatively small hole 31 in the end of the-retort. The hole 31 isclosed by a plate 32 in which one end of the shaft 27 is journaled. Thus the stirrer maybe insertedl and removedv without dismantling the retort land the centrifugal force of its rotation-will hold it extended as illustrated in Fig. 1.

Y A spray pipe 35 connected with a source of cold waterisprovided in the bottom of the retort 8.`

In carrying out my method, the used lubricatingoil to be reclaimed is placed in the open vessel or tank 1 and an acid such as sulphuric acid isintroduced to cause the precipitation of the heavier foreignmatter present in the oil.

The amount of sulphuric acid added will depend onthe character of the oil and the amount of foreign matter present and may be determined by the appearance and feel of the oil.

I then agitate the oil and acid by means of compressed air introduced into the bottom of the tank thru the pipe 4 to insure a thorough intermixture of the oil and acid. The oil is then allowed to stand to permit the precipitants to settle to the bottom in the 'form of sludge which may be drained oi and wasted thru the outlet 3.' u w After draining oi the sludge I introduce a sufficient quantity of a base, such as lime,;to neutralizet theacid and again agitate and4 then drain off and waste the resulting precipitants. Of course, should the used oil being treated contain very little or no;fo r eign`matter this step may be omitted. f Y

lftr lthe limeprecipitants are drained off, I add-i a quantity of fullers earth or-otherearthy material, approximately one-half to three-fourths pounds to the gallon and allow the resulting commixture to ow by gravity into the retort 8 thru the pipe l5. The commixture is then thoroughly intermixedby the stirrer 26 which is maintained in continuous operation to prevent the fullers earthffrom settling to the bottom of the retort.

The valves 9 and, 11 are then closed and the heating elements 25 are actuated to heat the commixture to a temperature of approximately 350 degrees F., under a resulting pressure of about 40 pounds to the square inch, which drives out the water content both free and emulsified.

As soon as the water content is driven out of the-oil, whichrequires approximatelyfone hour, depending upon the character of the oil being reclaimed, I open the valve l1 controlling the outlet-410 andpermit the steam to escape slowly thru the pipe 12 to the condenser 13, where it is condensed and wasted, butA is prevented from escaping to the atmosphere, the latterbeingundesirable because of its disagreeable odor. g

.Further by driving Off thewater content of the commixture in a closed retort, loss of oil, which would be carried off by the escaping steam is prevented and by then releasing the steam and allowing the pressure to fall gradually to atmospheric, the escaping steam cannot carry any of the oil with it.

It is to be noted that by carrying on the heating of the oil to drive off the water content, in a closed retort, I materially lessen the time required, for otherwise the heating of the oil at this temperature would cause it to boil over, and be ejected from the retort. In fact at a temperature of 350 degrees F. in an open retort, the oil would all be ejected within a relatively short time, approximately five minutes.

Further, thegradual fall of pressure permits a further gradual Vaporization of the water content ofthe commixture, prevented by the initial higher pressure and thus violent boiling or ebullition is prevented which would also tend to eject a portion of the oil from the retort.

The heating kof the commixture is then continued at a temperature of approximately 450 degrees F. to volatilize and drive oil the hydrocarbon components which comprise the gasoline and other more volatile hydrocarbons intermixed with the oil. l

It is to be noted that during this step, I may, if desirable, raise the temperature of the commixture suiiciently to volatilize and drive off a larger percentage of the lighter components of the lubrieatingv oil to produce a lubricating oil having a heavier body.

The escaping gases from the commixture which are condensed in the condenser 13 may either be wasted or saved for further treatment to separate the gasoline components from water and other undesirable components. However, it is essential that they be condensed and not allowed to escape to the atmosphere because of the explosive properties particularly at high temperature.

After the said volatile components of the commixtures are driven off, I introduce a small quantity of cold water thru a spray pipe 30 located in the bottom of the retort, which is immediately flashed into steam by the heat of the commixture and carries off the remaining more volatile components, foreign matter and other impurities and claries and deodorizes the oil.

By introducing cold water into the commixture, which immediately ilashes into steam, the volume of the water increases approximately 1200 times and thus produces an explosive effect, which breaks away the remaining solid particles intimately intermixed with the oil, which are carried away by the steam as it passes upwardly thru the oil.`

Finally, as the last step of my method, I open the valve 15 controlling the outlet 14 and discharge the commixture thru the pipe 16, to the cooling coils 17 and to the filter 19 where the fullers earth and other remaining solid particles are removed. Such cooling of the commixture is essential, for otherwise at a temperature above 450 degrees F. the oil would tend to flash into combustion on exposure to the atmosphere and in any event will become oxidized and turn black, which is of course to be avoided. i

Further, in order to avoid using a pump to draw the commixture from the retort 8 and force it thru the filter 19, I close the valve 11 at the end of the heating period and continue to inject Water, which, turning to steam, creates a'pressure in the retort and forces the commixture from the retortand thru the filter without auxiliary means.

By using steam for this purpose, I provide a gas, which does not react with the oil. To use air for this purpose would oxidize the oil and cause it to turn black which, as mentioned, is undesirable.

Finally when the retort 8 is completely empty, the steam tends to pass thru the cooling coils 17 and be condensed to water which would intermix with the oil, but the temperature of the oil in passing thru the said cooling coils is only lowered to approximately 220 degrees F. and thus the intermixed water immediately turns to steam and passes off in the form of vapor.

I claim:

1. The herein described method of reclaiming used lubricating oil comprising` mechanically agitating the oil and heating the oil under pressure in a closed retort to a temperature of approximately 350 F., to eiect removal of water from the oil by Vaporization and to restrain ebullition and the carrying off of particles of oil with the water vapor; then opening the retort and permitting the generated steam to escape gradually until pressure within the retort is reduced to atmospheric; then further heating the oil with the retort open to approximately 450 F. to drive off the more Volatile components of the oil and discharging these components from the retort thru a cooling coil; then, while maintaining the last mentioned temperature, clarifying and deodorizing the oil by introducing into the bottom thereof small jets of cold water whereby to cause ashes of steam to surge thru the oil, then withdrawing the oil from the retort thru a cooling coil without exposure to the atmosphere, and finally filtering it.

2. In the reclaiming of used lubricatingroil the herein described steps comprising first dehydrating the oil by heating the oil under pressure in a closed retort to a temperature of approximately 350 F., to effect removal of water from the oil by vaporization and to restrain ebullition and the carrying o of particles of oil with the Water vapor; then opening the retort and permitting the generated steam to escape gradually until pressure within the retort is reduced to atmospheric; then further heating the oil with the retort open to approximately 450 F. to drive oiic the more volatile components of the oil, then, while maintaining the last mentioned temperature, clarifying` and deodorizing the oil by introducing into the bottom thereof small jets of cold water whereby to cause fiashes of steam to surge thru the oil.

FREDERICK G. BAENDER.. 

